1. Field of the Invention
The present invention relates to an electronic equipment such as a VCR (video cassette recorder), etc., and in particular, to a link mechanism of a push-button device mounted to an operation panel of the front surface thereof.
2. Description of the Related Art
On the front panel of the electronic equipment, operating push-buttons are positioned, and in order to link the push-buttons to switches located on printed wiring circuit board, a link mechanism is provided. Conventionally, link mechanisms of various types and constructions have been developed and put into use.
Referring now to FIG. 1 and FIG. 2, the first example of link mechanism of the push-button device of conventional electronic equipment will be described. This link mechanism has a plurality of L-letter-shape lever members 180, and each lever member has a vertical pressing member 183 and a horizontal arm 184. Each lever member 180 is connected to a mount 185 via hinges 186.
On the outer surface of the pressing member 183, a protruding button 189 is mounted. The top end of the arm 184 is arranged on a push-button type switch 210 mounted on a printed wiring circuit board 200. As shown in FIG. 2, pressing the button 189 with a finger causes the L-letter-form lever member 180 to pivotally move around a pivot axis perpendicular to the paper surface passing through the hinges 186, and the top end of the arm 184 of the lever member moves downwards. This will activate the push-button type switch 210.
Referring now FIG. 3 and FIG. 4, the second example of link mechanism of the push-button device of conventional electronic equipment will be described. This link mechanism has a plurality of L-letter-shape lever members 190 (FIG. 3 and FIG. 4 shows only one of them), and each lever member has a vertical pressing member 193 and a horizontal arm 194. On the top end of the vertical pressing member 193, a hinge 192 is mounted and above the hinge 192, a mount 191 is fitted. The mount 191 is mounted to a cabinet of the electronic equipment.
On the outer surface of the pressing member 193, a protruding button 199 is mounted. The top end of the arm 194 is arranged on a push-button type switch 220 located on a printed wiring circuit board 200. As shown in FIG. 4, pressing the button 199 causes the L-letter-shape lever member 190 to pivotally move around the pivot axis perpendicular to the paper surface passing through the hinge 192, and the top end of the arm 194 of the lever member moves in the horizontal direction. This actuates the push-button type switch 220.
With the link mechanism of the push-button device of conventional electronic equipment, it was difficult to change the position of push-buttons resulting from design changes. For example, varying the push-button position along the vertical direction on pressing members 183, 193 causes the length of arm of moment of force to be changed, and the magnitude of force exerted on the push-button type switch varies. Varying the push-button position along the horizontal direction causes the line of action of force exerted on the switch to be changed, and the lever member is twisted. Consequently, the force applied to the push-button switch is varied and the operating feeling is degraded.
In the example of FIG. 3 and FIG. 4, the top end of the arm 194 moves in the horizontal direction. Consequently, in this example, it is necessary to use a longitudinal-type switch that is actuated by applying force in the lateral direction. The longitudinal-type switch has a disadvantage of high price as compared to a flat-type switches as used in the example of FIG. 1 and FIG. 2.
In these examples, the lever member is of a construction cantilevered by a hinge, and when this is fabricated by molding, the lever member is easy to be bent at the thinner portion of the hinge, and there is some possibility to generate defective products.
Consequently, it is an object of the present invention to provide an electronic equipment in which it is comparatively easy to freely choose the push-button position and a link equipment of such push-button device.
It is an object of the present invention to provide an electronic equipment equipped with a push-button device with excellent operability.
According to the present invention, in an electronic equipment comprising a link mechanism formed with one member equipped with a button for operating the electronic equipment and applied to operate an electric switch disposed in a printed wiring circuit board for a main circuit of the electronic equipment by the force applied to the button, the electronic equipment comprises
a first lever member whose one end is bendably connected to the electronic equipment via the first elastic portion and which is applied to be bent by the force applied to the button,
a second lever member whose one end is bendably connected to the electronic equipment via the second elastic portion and which protrudes in the direction opposite to the button and is equipped with an arm for operating the electric switch, and
a third elastic portion for connecting the first lever member to the second lever member and transmitting the displacement caused by the bend of the first lever member to the second lever member.
According to the present invention, in a link equipment comprising a link mechanism for transmitting the force applied to a button mounted to an electronic equipment to an electric switch mounted at a specified location of the electronic equipment and a frame-form portion equipped with a fitting portion for fixing to the electronic equipment, and the link mechanism and the frame-form portion are formed from one member, the link equipment comprises
a first lever member whose one end is bendably connected to the electronic equipment via a first elastic portion and which is bent by the force applied by the button,
a second lever member whose one end is bendably connected to the electronic equipment via the second elastic portion and which protrudes in the direction opposite to the button and is equipped with an arm for operating an electric switch, and
a third elastic portion for linking the first and the second lever members and for transmitting displacement caused by the bend of the first lever member to the second lever member. By the way, the elastic portion may be called a bent portion or hinge in embodiments of the present invention.
The printed circuit board for the main circuit is positioned so that the end of the board is close to or abuts the rear surface of the front panel. The link mechanism of the present invention connects between the button means on the front panel and the switch means on the printed circuit board. Accordingly, the printed circuit board for the main circuit can include the switch circuit and therefore it is not necessary to provide a printed circuit board for the switch circuit separately.
As described above, because the link mechanism is fixed on both sides and the first lever member and the second lever member rotate around a pivot axis different from each other, satisfactory operating feeling is obtained even when the push-button position is varied from top to bottom. To look at this from a different viewpoint, since the link mechanism has a construction to link two lever members with one linking member, varying the length of two lever members subtly varies the force for pressing the button and the stroke of moving the button, and a button device with satisfactory operation feeling is able to be obtained.